Piston for grease-guns



H. M. BOE.

'RISTON FOR GREASE GUNS. APPLICATION FILED Ju'LY 8. 191g.

1,377,660. Patented May 1o, 1921.

y WMM' UNITED srarss HANS M. BOE, OFMINNEAPOLIS, MINNESOTA.

PISTON FOR GREASE-GUNS. a

. Specification of Letters Patent. Patented May 10, 1921..

Application filed` July 8, 1918. Serial No. 243,976.

To all 'whom/25 may concern:

Be it known that I, HANS M. Bon, a citizen of the United States, resident of Minneapolis, county of Hennepin, State of Minne- Sota, have Vinvented certain new and useful YImprovements in Pistons` for Grease-Guns,

of which the following is a specification.

Inthe manufacture of grease guns or apparatus for dispensing grease or oils, it has been necessaryv to provide pistons of different weight according to the character of the grease or oil to be dispensed or delivered. For a heavy oil, a heavypiston must be used and for a lighter oil a correspondingly lighter piston must be provided to insure the successful operation of the device.

They object of my invention is to provide the grease container with a piston ofsuch construction that it can be readily adapted for heavy or light lubricating material and so constructed that the container may be filled without the necessity of removing the entire piston therefrom. A further object is to provide a `piston adapted for tanks of different diameter and a combination piston which may be of greaterdiameter than the cover used for refilling the container.

A further object is to provide a piston which can be readily adapted for containers `of different diameters. Y

- the piston ring and the piston proper fitting. therein,

Fig. 4 is a bottom view of the piston,

Fig. 5 is a sectional view of a portion of the container, of small size, showing the piston adapted for this diameter of container. i

In the drawing, Qrepresents a container havinga bottom 3, eXit ropening 4 land a ring 5 whereon a cover 6 is moimted. A stud 7 is provided on the cover to receive a collar 8 whereto the series of forked arms 9 are pivoted having ends 10 for engaging the Shanks of bolts 11, said arms being fulcrumed on the cover for pressing it down to its seat. 12 is a wing nut mounted on the stud 7 and engaging the collar 8. 13 is an air intake valve and 14 an indicator carried bythe cover. ring or section of the piston. This ring is preferably'made up of a series vof wooden rings (though metal may be used) placed one upon the other and secured together and having a bail 16 for convenience in lifting it out of the container or placing it therein. This bail may be used for lifting the piston 15 represents the outer tothe top of the container preliminary to reloading and particularly if the diameter of the tank is greater than the cover for said ing or dispensing light oils, as it will float' thereon and gradually slide down to the bottom of the tank as the lubricating material is discharged.

Within the central opening 18 in this piston I provide a secondary piston 19 hav-' ing preferably a central core orv block with a peripheral fabric 20, preferably canvas, secured thereto and 'having outwardly turned edges to contact with the peripheral edges of plates 21 which are secured to the a' top and bottom of the auxiliary piston by a bolt 22. VThis bolt has a nut 23 at one end thereof and a head 24 is provided at the opposite end inposition to be engaged and concealed by a cap 25. Thefbottom of this cap forms a valve for closing the port 4 in case the piston should drop to the lower end of the tank before the air has been entirely exhausted from thepi e. The cap in the bottom of the piston as the function of closing the port ywhen the tank is emptied of lubricating material, thereby preventing the i remaining air charge from escaping through the discharge pipe and hose.

twelve inches or more. e

The piston 19 has a loop 26 thereon for the attachment of a line from the indicator, so that the position of the piston will always determine the location of the indicator and the amount that has been discharged from the container. The line from the indi cator may be connected to the bail of the ring instead of to the inner section, if preferred. The plates 21 are preferably of iron and exert considerable downward force onV the piston, causing it to hold its place in the container with a body of heavy oil or grease therein, withouthowever, sinking to the bottom of the container as usually is the case and would be true of this application if this piston was used with a lighterV grade of oil than was intended for a piston of this type. This weighted piston keeps the contents of the container leveled upon top and insures a more accurate measure. .It also overcomes the tendency of the lubricating material to Yfunnel downl toward the discharge opening. The core being of Wood, the upper and lower plates may be removed and the piston used in light oil without the removable disks, but when the piston is used in heavy oil or grease, one or both of the plates 21 are mounted on the bolt so that the piston, will then be of suiiicient weight to properly feed the lubricating material out of the tank. The float part of the piston and piston ring may be made Aof metal or from cork or other suitable material, but the piston only affects the measuring of the lubricant to the extent rthatV itv keeps`.the top of the contents of thegcontainer level, or nearly so. The under side of the pistonl ring 15 is provided with clips 27-on which the inner piston'may rest when inserted in the4 ring and the peripheral covering 20, of canvas or other suitable material, encircling the piston 19, will have sufficient friction with the ring to :hold the inner piston in 'place and the indicator cable 29 may be connected to the loop 26 that is mounted on the upper end of the bolt 22, the weight of the piston holding it in place in the ring though provision may be made for connecting it to the ring, if preferred. lVith this construction of piston it is not necessary to use a larger cover for the container than is required for vinserting the piston 19. In ksuch case the floating piston ring is liftedby means of its bail yup under the head of the container while it is being` refilled. The diameter of the opening for a container is necessarily limited on account of the difficulty of getting an air-tight joint, even with a cover locking device. 1 have found that a seven inch opening is about the limit, while the'diameter of the tank may be From the foregoing it will be noted that the outer or ring section is preferablyv of and separable therefrom without removal of the ring from the container and an indicating device for said container having a flexible connection with said piston.

2. The combination, with a container, of a piston fitting therein and comprising an inner and an outer section, said inner section being separable from said outer section without removal of the outer section from the container and having means for attaching it to Van indicating device cable.

3. The combination, with a "container, of a piston fitting therein and comprising an inner andan outersection, said outer section being comparatively light in weight and said inner section being comparatively heavy and having means for connecting it with an indicating device cable, the inner section being separable from the outer section without removal of the latter from the 'container.

. 4:. The combination, with a container, of a piston fitting therein and comprising an inner and an outer section, said inner section having ay comparatively light core and metalplates securedto the upper and under side thereof, said sections being heldtogether by frictional contact and said inner section having means for connection with an indicator cable.A

5. The combination, with a container, of a piston fitting therein and comprising an outer piston ring composed of comparatively light material havin-g clips' on the under side thereof, projecting into the opening therethrough, and a comparatively heavy inner section fitting Vwithin the opening in said ring and seated. on said clips, and flexible means 'connected to said piston.

6. The combination, with a container I container through the cover opening without Y removing said outer section.,

7. The combination, with av container adapted to contain a lubricating agentfhavg ing a discharge opening in the bottom thereof and a removable cover, of a piston fitting Within said container and comprising a comparatively light outer ring section and an inner disk section fitting Within said ring section and said inner disk section having a yielding peripheral covering for engaging the Wall of said outer section, said piston floating on the material in said container and said disk section being removable for 1G lilling purposes independently of the outer section.

In Witness whereof I have hereunto set my hand this 21st day of June 1918.

HANS M. BOE. 

